package com.jstarcraft.ai.jsat.classifiers.evaluation;

/**
 * Evaluates a classifier based on the Recall rate, where the class of index 0
 * is considered the positive class. This score is only valid for binary
 * classification problems.
 * 
 * @author Edward Raff
 */
public class Recall extends SimpleBinaryClassMetric {

    private static final long serialVersionUID = 4832185425203972017L;

    /**
     * Creates a new Recall evaluator
     */
    public Recall() {
        super();
    }

    /**
     * Copy constructor
     * 
     * @param toClone the object to copy
     */
    public Recall(Recall toClone) {
        super(toClone);
    }

    @Override
    public double getScore() {
        return tp / (tp + fn);
    }

    @Override
    public boolean equals(Object obj) {
        if (this.getClass().isAssignableFrom(obj.getClass()) && obj.getClass().isAssignableFrom(this.getClass())) {
            return true;
        }
        return false;
    }

    @Override
    public int hashCode() {
        return getName().hashCode();
    }

    @Override
    public Recall clone() {
        return new Recall(this);
    }

    @Override
    public String getName() {
        return "Recall";
    }

}
